sectional density\'s effect on bullet performance I know that it is interrelated with B.C., but I'm not sure what the difference is, and it's application to LR??

Re: sectional density\'s effect on bullet performance Me neither but here's some stuff I found. Relationship to BC: http://ffden-2.phys.uaf.edu/212fall2001_Web_projects/Isaac%20Rowland/Ballistics/pages/BCcalc.htm Someone else's paper: http://ffden-2.phys.uaf.edu/212fall2001_Web_projects/Isaac%20Rowland/Ballistics/pages/BCcalc.htm From Sierra: http://www.sierrabullets.com/xring/index.cfm?fuseaction=Vol7no3 Lots of stuff: http://www.exteriorballistics.com/ebexplained/index.cfm

Re: sectional density\'s effect on bullet performance sscoyote, SD or sectional density is a measure of mass to cross section of a projectile. For a given caliber, higher SD means greater penetration IF ALL OTHER THINGS ARE EQUAL. SD is used to calculate ballistic coefficient(BC). BC is a measure of how well a projectile retains velocity in comparison to a standard projectile. Any number less than 1 means it retains less velocity at a given range, 1 is equal, and more than 1 denotes more retained velocity. Another way of looking at it is that it reflects a bullet's drag characteristics. In calculating BC, the bullet's FORM is considered in relation to SD, which presents a NON-DIMENSIONAL value for comparison. BC for a given form is directly proportional to SD. Try "Understanding Firearm Ballistics" by Robert Rinker. It is a cheap and time saving education, which cover interior/exterior and terminal ballistics. Luck.